Intradermal, Subcutaneous or Intramuscular Administration of Hepatitis B Vaccine: Side Effects and Antibody Response

Abstract

The immune response after vaccination with a plasma-derived hepatitis B unit vaccine (MSD) administered intradermally or subcutaneously in 2 μg doses was compared to the recommended 20 μg dose administered intramuscularly. The trial was performed in 58 healthy volunteers 20–43 (mean 30) years old. No statistically significant difference in seroconversion rate was observed when the intradermal (i.d.) (2 μg) and intramuscular (i.m.) (20 μg) routes were compared (100% and 96% seroconversion, respectively). The 2 μg dose administered subcutaneously gave a seroconversion rate of only 63%. The intradermal and i.m. routes also gave significantly higher mean titers of anti-HBs than the subcutaneous route (p<0.005). No severe reactions occurred and local reactions were seen almost exclusively in those vaccinated intradermally. These reactions included mainly discoloration, itching and nodule formation at the site of injection. The intradermal route ought to be considered for administration of hepatitis B vaccine since the dosage can be reduced to 1/10 without affecting the antibody response. Correct intradermal deposition of the vaccine is, however, crucial for an adequate immune response. This is probably the main disadvantage if large-scale vaccination programs should be carried out in developing countries using i.d. immunization.